mmc: card: Add RPMB support in IOCTL interface

RPMB partition is accessing though /dev/block/mmcXrpmb device
User callers can read and write entire data frame(s) as defined
by JEDEC Standard JESD84-A441, using standard IOCTL interface.

Signed-off-by: Alex Macro <alex.macro@stericsson.com>
Signed-off-by: Loic Pallardy <loic.pallardy@stericsson.com>
Reviewed-by: Namjae Jeon <linkinjeon@gmail.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Krishna Konda <kkonda@codeaurora.org>
Signed-off-by: Chris Ball <cjb@laptop.org>

1 files changed, 64 insertions, 0 deletions

diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index 1d341f3878ec..21056b9ef0a0 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -127,6 +127,10 @@ enum mmc_blk_status {
 module_param(perdev_minors, int, 0444);
 MODULE_PARM_DESC(perdev_minors, "Minors numbers to allocate per device");
 
+static inline int mmc_blk_part_switch(struct mmc_card *card,
+                                      struct mmc_blk_data *md);
+static int get_card_status(struct mmc_card *card, u32 *status, int retries);
+
 static struct mmc_blk_data *mmc_blk_get(struct gendisk *disk)
 {
         struct mmc_blk_data *md;
@@ -358,6 +362,38 @@ out:
         return ERR_PTR(err);
 }
 
+static int ioctl_rpmb_card_status_poll(struct mmc_card *card, u32 *status,
+                                       u32 retries_max)
+{
+        int err;
+        u32 retry_count = 0;
+
+        if (!status || !retries_max)
+                return -EINVAL;
+
+        do {
+                err = get_card_status(card, status, 5);
+                if (err)
+                        break;
+
+                if (!R1_STATUS(*status) &&
+                                (R1_CURRENT_STATE(*status) != R1_STATE_PRG))
+                        break; /* RPMB programming operation complete */
+
+                /*
+                 * Rechedule to give the MMC device a chance to continue
+                 * processing the previous command without being polled too
+                 * frequently.
+                 */
+                usleep_range(1000, 5000);
+        } while (++retry_count < retries_max);
+
+        if (retry_count == retries_max)
+                err = -EPERM;
+
+        return err;
+}
+
 static int mmc_blk_ioctl_cmd(struct block_device *bdev,
         struct mmc_ioc_cmd __user *ic_ptr)
 {
@@ -369,6 +405,8 @@ static int mmc_blk_ioctl_cmd(struct block_device *bdev,
         struct mmc_request mrq = {NULL};
         struct scatterlist sg;
         int err;
+        int is_rpmb = false;
+        u32 status = 0;
 
         /*
          * The caller must have CAP_SYS_RAWIO, and must be calling this on the
@@ -388,6 +426,9 @@ static int mmc_blk_ioctl_cmd(struct block_device *bdev,
                 goto cmd_err;
         }
 
+        if (md->area_type & MMC_BLK_DATA_AREA_RPMB)
+                is_rpmb = true;
+
         card = md->queue.card;
         if (IS_ERR(card)) {
                 err = PTR_ERR(card);
@@ -438,12 +479,23 @@ static int mmc_blk_ioctl_cmd(struct block_device *bdev,
 
         mmc_claim_host(card->host);
 
+        err = mmc_blk_part_switch(card, md);
+        if (err)
+                goto cmd_rel_host;
+
         if (idata->ic.is_acmd) {
                 err = mmc_app_cmd(card->host, card);
                 if (err)
                         goto cmd_rel_host;
         }
 
+        if (is_rpmb) {
+                err = mmc_set_blockcount(card, data.blocks,
+                        idata->ic.write_flag & (1 << 31));
+                if (err)
+                        goto cmd_rel_host;
+        }
+
         mmc_wait_for_req(card->host, &mrq);
 
         if (cmd.error) {
@@ -479,6 +531,18 @@ static int mmc_blk_ioctl_cmd(struct block_device *bdev,
                 }
         }
 
+        if (is_rpmb) {
+                /*
+                 * Ensure RPMB command has completed by polling CMD13
+                 * "Send Status".
+                 */
+                err = ioctl_rpmb_card_status_poll(card, &status, 5);
+                if (err)
+                        dev_err(mmc_dev(card->host),
+                                        "%s: Card Status=0x%08X, error %d\n",
+                                        __func__, status, err);
+        }
+
 cmd_rel_host:
         mmc_release_host(card->host);